Dead wood dynamics in Fennoscandian forests

Application period: 11 June – 10 August, 2026

Research project description

Dead wood is a key structure for biodiversity in the Fennoscandian boreal forests. The progression of dead wood through successive stages of decomposition determines both the availability of specialized habitats for saproxylic species and the rate at which carbon is released back into the atmosphere. Despite this recogized importance, the temporal dynamics associated with dead wood habitats and carbon retention remain poorly quantified at large spatial scales, limiting our ability to predict ecosystem responses to forest management, forest restoration, and climate change.

This PhD project investigates the dynamics of dead wood in Fennoscandian boreal forests, using National Forest Inventory data from Finland, Norway and Sweden. Building on this large-scale, longitudinal data, the project quantifies how characteristics of the tree, and its environment influence the rates at which dead wood progresses through decay stages. Depending on the interests of the candidate, the project can be also be developed towards a stronger focus on old-growth forests, with physically and chemically highly diverse dead wood.

Academic background and skills of the applicant

An ideal candidate holds a master’s degree in forest ecology, ecology, environmental science, or a closely related field. The candidate is expected to have a strong understanding of forest ecosystem processes, ideally including dead wood dynamics, decomposition, and boreal forest ecology. Solid quantitative skills and experience in statistical modelling and data analysis using R or a comparable programming environment are required. Prior experience with Bayesian approaches, hierarchical models, and the ability to work with large, complex, and spatially structured datasets are considered an advantage. The selected candidate must fulfil the language skills requirements of the Doctoral Programme in Science, Forestry and Technology at UEF (see https://www.uef.fi/en/degree-programme/doctoral-programme-in-science-forestry-and-technology (Eligibility and admission criteria)).

Doctoral programme and research group

Doctoral education in the University of Eastern Finland is arranged in seven discipline specific or thematic doctoral programmes. This research project will be located in the Doctoral Programme in Science, Forestry and Technology, and the submitting department is the School of Forest Sciences.

The candidate will join the Forest Disturbance Ecology research group that studies the disturbance dynamics, biodiversity, and long-term development of boreal forests and the treeline ecotone. The research has broad foci related to forest ecology and disturbances, with wildfires, dead wood and biodiversity, disturbances in treeline areas, and the natural disturbance dynamics in protected areas as some of the key themes. The particular expertise of the group is in dendrochronology, and it maintains the tree ring lab of the University of Eastern Finland.

Partners / Secondments

Mid-Sweden University, hosted by professor Bengt-Gunnar Jonsson

Other interdisciplinary, international, intersectoral collaboration

This project includes potential collaboration with Natural Resources Institute Finland (LUKE) and The Norwegian Institute of Bioeconomy Research (NIBIO).

Intersectoral and interdisciplinary collaboration is strengthened through DP-FOBI’s three summer schools involving academic supervisors, non-academic partners, and other stakeholders, enabling hands-on interaction and knowledge exchange.

Supervisors and related research

Tuomas Aakala

Tuomas Aakala is a professor of forest disturbance ecology at the University of Eastern Finland. Related to the topic of this research project, Aakala has worked on a wide range of research questions related to dead wood, its dynamics, and its role for biodiversity and carbon cycling in different parts of the boreal zone. Methodologically, this has involved the use of field data, dendrochronological approaches and, more recently, dead wood data from national forest inventories.

Aakala leads the research group on forest disturbance ecology at UEF, with two senior researchers, and PhD and MSc students. The group is active in both national and international collaborations, including research networks related to natural forests, dendrochronology, and dead wood ecology. Aakala is currently supervising four doctoral students, with two completed earlier. In addition, he is co-supervising three doctoral students in Finland and Sweden. The research group also actively engages MSc students in various research projects, including dead wood ecology and dynamics, currently with six students working on their theses.

Hannes Pasanen

Aakala, T., Storaunet, K.O., Jonsson, B.G. and Korhonen, K.T., 2024. Drivers of snag fall rates in Fennoscandian boreal forests. Journal of Applied Ecology, 61(10), pp.2392-2404.

Nirhamo, A., Santos, P., Günther, M., Kouki, J. and Aakala, T., 2026. Community dynamics of lignicolous lichens on standing deadwood in a 275‐year chronosequence. Oikos, p.e11835.

Aakala, T., Heikkinen, J., 2024. Harmonized decay classification for dead wood in Nordic national forest inventories. Scandinavian Journal of Forest Research 39:1-7.

Pasanen, H., Junninen, K., & Kouki, J. (2014). Restoring dead wood in forests diversifies wood-decaying fungal assemblages but does not quickly benefit red-listed species. Forest Ecology and Management, 312, 92-100.

Pasanen, H., Juutilainen, K., & Siitonen, J. (2019). Responses of polypore fungi following disturbance-emulating harvesting treatments and deadwood creation in boreal Norway spruce dominated forests. Scandinavian Journal of Forest Research, 34(7), 557-568.